Wet-spinning apparatus



April 10, 1962 M. SONNlNO WET-SPINNING APPARATUS Filed May 5. 1960 T0GUIDE ROLL AND NEXT STEP 38 IN PROCESS IS r lo/ I04 I I 26x 2e 52 I 4242 50 8 4O 76 f 76 64 l 56 FROM SUPPLY SOURCE OF SP/NN/NG' SOLUT/ONINVENTOR. MAR/0 SON/V/NO BY fi/mst .4? A

United States Patent of Maine Filed May 3, 1960, Ser. No. 26,477 9Claims. (Cl. 18-8) This invention relates broadly to wet-spinningapparatus and, more pmticularly, to such apparatus which permits thespun material to travel upwardly in a coagulating bath without immersionof the spinning head in the bath.

It was known prior to the present invention to arrange the spinningnozzle at the end of a tube and to cause the coagulating liquidcomprising the spinning bath to pass through the tube in the directionof travel of the extruded filaments or thread. In many cases, theprior-art practice has involved positioning the tube horizontally andthe coagulating liquid was usually arranged to flow from a supply sourcethrough the tube in front of which the spinning nozzle or spinnerettehad been placed. In the latter arrangement, immediately after extrusionof the spinning solution into the coagulating liquid to form filaments,the coagulating liquid carried the threads with it, and filaments havingimproved properties were obtained due to the favorable direction of flowof the coagulating liquid. In such cases, the immersion of thespinnerette and the spinning head in the coagulating liquid and theremoval of the spinnerette, when it had to be changed, caused no greatdifficulty except for the tirne lost in draining the assembly.

In the suggestions found in the prior art for so-called upward Spinningthe spinning head is immersed in the coagulating liquid. This may not beparticularly objectionable when the coagulating liquid is at roomtemperature or thereabouts, but is objectionable when the liquidcoagulant is at a reduced temperature such as, for example, 0 C. orlower and the spinning solution being extruded through the orifices ofthe spinnerette is at an elevated temperature, e.g., 50 or 60 C. orhigher, e.g., up to 80 or 90 C.

The present invention provides new and improved wetspinning apparatuswherein the spinning head and the spinnerette, which together form thespinning assembly, are not immersed in the coagulating liquid withconcurrent advantages in heat transfer, cost saving, equipmentsimplification and efficient and ample distribution of the coagulatingliquid. Furthermore, in the apparatus of the present invention, thespinning head is outside of the coagulating liquid. This is a matter ofparticular importance when the coagulatng liquid is one that is at atemperature of the order of 10 C. to or C. Also, the coagulating chamberfor each head is removable without disturbing the performance of theother heads of a particular series. Furthermore, the spinnerette is insuch a position that the extruded filaments and the face of thespinnerette can be readily observed. The practical advantages of such aconstruction will be readily apparent to those skilled in the art, whowill also quickly appreciate that the invention provides a long-desiredneed in the art.

It is, accordingly, a primary object of the present invention to providean improved wet-spinning apparatus where in the spinning head and thespinnerette are not immersed in the coagulating liquid with theaccompanying advantages set forth in the preceding paragraph.

Other advantages of the invention will be apparent to those skilled inthe art from the following more detailed description and the singlefigure of the accompanying draw- The novel features that arecharacteristic of the inven- "ice tion are set forth in the appendedclaims. The invention, itself, however, will best be understood byreference to the description which follows, when considered inconnection with the accompanying drawing in which the single FIGUREshows a side sectional view of apparatus embodying the invention.

Referring to the drawing, which is merely illustrative of apparatusembraced by the invention, there is shown by way of illustrationwet-spinning apparatus embodying the invention and which comprises anelongated chamber 10 having side walls and which is open at its upperend. Within the chamber 10 there is an open-ended spinning tube 12 whichhas a comically-shaped main body portion 14 and, preferably, anoutwardly-flaring mouth 16 at its apex. Such an outwardly-flaring orfunnel-shaped mouth obviates or minimizes turbulence as the coagulatingliquid 32 overflows into the reservoir 20. Within the chamber 10 thereis a wall 18 which joins the upper portion of the spinning tube 12 tothe inner, upper part of the chamber 10, thereby sectionally dividingthe chamber 10 to form an upper reservoir 20 and a lower reservoir 22.Closure and sealing means 24 are provided for closing and sealing thelower end of the elongated chamber 10 and for supporting a spinnerette26 in an upward-spinning position. The lower end 23 of the spinning tube12 is so spaced from the upper part of the closure and sealing means 24as to form a narrow, annular passageway 30 therebetween. Through thisannular passageway coagulating liquid 32 can be introduced into thespinning tube 12 at a level below the face 34 of the spinnerette 26.Means including a conduit 36 are provided for introducing a coagulatingliquid into the upper part of the lower reservoir 22 and, also, meansincluding a conduit 38 for withdrawing coagulating liquid. from thelower part of the upper reservoir 20. I

The closure and sealing means 24 advantageously include, as shown in thedrawing, a combination of a cap or coupling nut 40, an O-ring sealingmember 42 and an end-closing member 44 that can be detachably united tothe cap 40 and upon which member the spinnerette 26 can be mounted in anupward-spinning position.

The cap 40 is adapted to fit within the elongated chamber 10 at thelower end thereof, the upper portion 46 of the cap being also adapted tofit within the bottom of the spinning tube 12 and being spaced from thelower end 28 thereof so as to form the aforementioned narrow, annularpassageway 30. This cap may be formed, for instance, of nylon,polymerized tetrafiuoroethylene, or of any suitable material which hasthe desired heatinsulating properties and is resistant to attack by theparticular liquids with which it comes in contact.

The cap 40 has a central, vertical opening 48 therein. The upper part ofthis opening is adapted to receive the spinnertte 26 therein, the sidewall(s) of the spinnerette abutting the side wall(s) defining theaforesaid upper part of the opening 48. The lower part of this openingis of larger diameter than that of the said upper part thereof, the walldefining this larger diameter, lower part of the opening 48 beingthreaded; that is, the cap has an internally threaded portion into whichcan be screwed the externally threaded upper extension 50 of theend-closing member 44.

The cap 40 also has an annular slot 52 in the broadest part of its outerperiphery. This slot has therein an O- ring sealing member 42 which maybe formed of neoprene or other plastic or other material capable offunctioning as a gasket material and which is impervious to the actionof the particular coagulating liquid 32 employed in the use of theapparatus. This Q-ring provides a seal between the cap or coupling nut40 and the elongated chamber 10.

The end-closing member 44 has an externallythreaded upper extension 50,which has an annular recess 56 in its upper wall and an annular gasket58 therein adapted to contact the lip 60 of the spinnerette 26. Themember 44 can be formed of the same kind or type of material'describedabove with reference to the cap 4% Means also are provided for couplingthe end-closing member 44 to the elongated chamber 10. These means maytake the form of a member comprising a bottom wall 62 having a sidewall(s) 64 and an extension 50. The extension 50 is provided with theaforementioned recess 56 in which is placed the gasket material 53comprised, for example, of neoprene rubber or of any other materialwhich is resistant to attack by the spinning solution or dope which isbeing conducted to the spinnerette 26 through the pipe or conduit 66.

The bottom wall 62 and the extension 50 have a cen tral, verticalopening 68 therein which is aligned with the opening 48 in the cap 49.The wall defining the lower part of this opening 68 is threaded so thatthe conduit 66 having an externally threaded end or terminal section 72can be screwed into the threaded opening 68 in the end-closing member44.

The coupling nut 74 provides means whereby the endclosing member 44 canbe tightened at the abutment '76 between said member and the lower partof the elongated chamber 16. This coupling nut also provides meanswhereby the spinnerette 26 can be locked into place.

The open-ended inlet conduit 36 leads to an opening 78 in the upper part80 of the side wall of the lower reservoir 22. Means also are providedfor feeding a coagulating liquid into the open end 82 of the inletconduit 36. The open-ended conduit 36 advantageously may have afunnel-shaped mouth 84. The means for feeding a coagulating liquidthereto include, for example, a feed vessel 86 positioned above saidfunnel-shaped mouth and having side walls 38 and 9t) and a bottom wall92, which vessel is adapted to receive feed coagulating liquid 32therein. A tube 94 passes through the bottom wall 92 of said vessel andis adapted to be plugged when the apparatus is not in operation. Thistube is vertically aligned with the aforesaid mouth 84 of the inletconduit 36.

Suitable means also are provided for preventing the coagulating liquidfrom overflowing from the feed ves- Sol 86. Such means advantageouslymay take the form of a conduit 96 for carrying excess coagulating liquidfrom the feed vessel 86 to the discharge vessel or sump 98.

The conduit 96 advantageously may have a funnelshaped mouth 109. Themouth of this funnel is above the normal level of liquid in the feedvessel 86. When this normal level of liquid is excessive, it enters themouth 100 of the conduit 96 and is connected through this conduit to thedischarge vessel or sump 98.

Suitable means (not shown) are provided for recirculating thecoagulating liqud from the sump 93 to the feed vessel 86, and for addingmake-up liquid coagulant to the latter vessel as and when needed.

In ordinary pilot-plant and commercial operations the feed vessel 86 andthe discharge vessel or sump 98 are in the form of long troughs orrectangular vessels with a plurality of spinning assemblies, e.g., 15 to500 or more, positioned adjacent thereto as indicated in theaccompanying drawing. The spinning assemblies may be arranged along oneor both sides of such troughs.

In operation, the spinning assembly can be removed for changing of thespinnerette 26 as desired or as may be required; and during this time,after plugging (e.g., with a cork or other stopper) the top of the tube94, the coagulating liquid will flow from the feed vessel or trough 86to the discharge Vessel or sump 98 without interfering with thespinnerette change. Once the spinnerette 26 is ready for threading-up,the elongated chamber 10 with its inner, open-ended, conically-shapedspinning tube 12 is connected with the cap or coupling nut 40, and theflow of coagulating solution will begin immediately upon removal of theplug from the top of the tube 94.

In operation, the coagulating solution travels upvardly concurrentlywith the extruded filamentary material 192 into the conical chamber 194of the spinning tube 12, which chamber during operation of theapparatus, contains coagulating liquid 32. The conical shape makespossible an increase in the velocity of the coagulating liquid as thefreshly coagulated filaments become stronge The filaments that form atthe face 34 of the spinnerette 26, are led under moderate tension, afterleaving the coagulating bath, to a guide means (e.g., a roll) and thenceto the next step in the process.

From the foregoing description it will be noted that the spinning headis outside of the coagulating liquid. This is a matter of considerablepractical importance when the coagulating liquid is one which ismaintained at a low temperature, e.g., 0 C. and below as is describedmore fully in, for instance, Cresswell US. Patent No. 2,558,730. It isalso to be noted that the spinning chamber for each head is removablewithout disturbing the performance of the other heads employed in aparticular series. Also, the spinnerette is in such a position that theextruded filaments and face of the spinnerette can be observed.

In brief, the wet-spinning apparatus of the present invention provides anew and unobvious arrangement whereby the spinning head is not immersedin the coagulating liquid with the attendant advantages of efficiency inheat transfer, cost saving in operation, equipment simplification andadequate and effective distribution of the coagulating liquid.

The apparatus of the present invention is applicable for use in anywetaspinning operation, but is especially useful in the wet-spinning ofa solution of a polymer of acrylonitrile wherein such a solutionnormally is extruded into a coagulating bath maintained at a temperaturebelow +l0 C., e.g., from --9 C. to '5 C. Such spinning solutions andcoagulating baths (as well as other solutions and baths that can be usedin practicing the present invention) are described in, for instance,Patents 2,558,730, -731, -732, -733, -735 and -78l; 2,6l4,- 289;2,777,751; and in the patents referred to in the above-identifiedpatents.

I claim:

1. Wet-spinning apparatus comprising an elongated chamber having sidewalls and which is open at its upper end; an open-ended spinning tubewithin said chamber, said tube having a conically-shaped main bodyportion; a wall within said chamber joining the upper portion of thesaid spinning tube to the inner, upper part of the chamber, therebysectionally dividing the interior of the chamber to form an upperreservoir and a lower reservoir; closure and sealing means for closingand sealing the lower end of the said elongated chamber and forsupporting a spinnerette in an upward-spinning position such that theface of the spinnerette is in approximately the same horizontal plane asthat of the uppermost surface of the said closure and sealing means, thelower end of the said spinning tube being so spaced from the upper partof said closure and sealing means as to form a narrow, annularpassageway therebetween, and through which passageway coagulating liquidcan be introduced into the lower part of the said spinning tube at alevel below that of the face of the said spinnerette; means including aconduit for introducing a coagulating liquid into the upper part of thesaid lower reservoir; and means including a conduit for withdrawingcoagulating liquid from the lower part of the said upper reservoir.

2. Wet-spinning apparatus as in claim 1 wherein the elongated chamber isa cylindrical, elongated chamber and the comically-shaped main bodyportion of the spinning tube has an outwardly-flaring mouth at its apex.

3. Wet-spinning apparatus as in claim 1 wherein the closure and sealingmeans for closing and sealing the lower end of the said elongatedchamber and for supporting a spinnerette in an upward-spinning positioninclude, in combination, a cap, an O-ring sealing member and anend-closing member that can be detachably united to said cap and uponwhich member a spinnerette can be mounted in an upward-spinningposition.

4. Wet-spinning apparatus comprising a cylindrical, elongated chamberhaving side walls and which is open at its upper end; an open-endedspinning tube within said chamber, said tube having a conicallyashapedmain body portion with an outwardly-flaring mouth at its apex; a Wallwithin said chamber joining the upper portion of the said spinning tubeto the inner, upper part of the chamber, thereby sectionally dividingthe interior of the chamber to form an upper reservoir and a lowerreservoir each having a side wall; an open-ended inlet conduit leadingto an opening in the upper part of the side wall of the lower reservoir;means for feeding a coagulating liquid into the open end of said inletconduit; an open-ended outlet conduit leading from an opening in thelower part of the side wall of the upper reservoir; a discharge receiverpositioned to receive coagulating liquid that flows from the open end ofsaid outlet conduit when the apparatus is in operation; closure andsealing means for closing and sealing the lower end of the saidelongated chamber and for supporting a spinnerette in an upward-spinningposition such that the face of the spinnerette is in approximately thesame horizontal plane as that of the uppermost surface of the saidclosure and sealing means, the lower end of the said spinning tube beingso spaced from the upper part of said closure and sealing means as toform a narrow passageway therebetween, and through which passagewaycoagulating liquid can be introduced into the lower part of the saidspinning tube at a level below that of the face of the said spinnerette,said closure and sealing means including, in combination, a cap, anO-ring sealing member and an end-closing member that can be detachablyunited to said cap and upon which member a spinnerette can be mounted inan upward-spinning positon.

5. Wet-spinning apparatus as in claim 4 wherein the open-ended inletconduit has a funnel-shaped mouth and the means for feeding acoagulating liquid thereto include a feed vessel positioned above saidfunnel-shaped mouth, said vessel having side walls and a bottom wall andbeing adapted to receive feed coagulating liquid therein; a tube withinsaid feed vessel that passes through the bottom wall thereof, which isadapted to be plugged when the apparatus is not in operation, and whichis vertically aligned with the aforesaid mouth of the said inletconduit.

:6. Wet-spinning apparatus as in claim 5 which additionally includesmeans for preventing coagulating liquid from overflowing from the saidfeed vessel.

7. Wet-spinning apparatus as in claim 6 wherein the means for preventingcoagulating liquid from overflowing from the feed vessel includes aconduit for carrying excess coagulating liquid from the said feed vesselto the said discharge vessel.

8. Wet-spinning apparatus as in claim 4 which additionally includes aconduit detachably united to the endclosing member of the definedclosure and sealing means and through which conduit spinning solutioncan be passed and thence through a passageway leading to the spinnerettethat, in operation, is mounted on said end-closing member in anupward-spinning position.

9. Wet-spinning apparatus comprising a cylindrical, elongated chamberhaving side walls and which is open at its upper end; an open-endedspinning tube within said chamber, said tube having a conically shapedmain body portion with an outwardly-flaring mouth at its apex; a wallwithin said chamber joining the upper portion of the said spinning tubeto the inner, upper part of the chamber, thereby sectionally dividingthe interior of the chamber to form an upper reservoir and a lowerreservoir; closure and sealing means for closing and sealing the lowerend of the said elongated chamber and for supporting a spinnerette in anupward-spinning position such that the face of the spinnerette is inapproximately the same horizontal plane as that of the uppermost surfaceof the said closure and sealing means, the lower end of the saidspinning tube being so spaced from the upper part of said closure andsealing means as to form a narrow, annular pasageway therebetween, andthrough which passageway coagulating liquid can be introduced into thelower part of the said spinning tube at a level below that of the faceof the said spinnerette, said closure, sealing andspinnerette-supporting means including, in combination, a cap adapted tofit within said elongated chamber at the lower end thereof and the upperportion of said cap being also adapted to fit within the bottom of saidspinning tube and spaced therefrom so as to form the aforementionednarrow, annular passageway, said cap having a central, vertical openingtherein, the upper part of said opening being adapted to receive aspinnerette in an upward-spinning position, said spinnerette having alip, and the lower part of said opening being of larger diameter thanthat of the said upper part thereof and the wall defining said lowerpart being internally threaded, said cap also having an annular slot inthe broadest part of its outer periphery, said slot having therein anO-ring sealing member, and an end-closing member having anexternally-threaded upper extension which is screwed into theinternally-threaded portion of the said cap, said end-closing memberhaving a central, vertical opening therein which is aligned with theopening in the said cap, the said extension having an annular recess inits upper wall and an annular gasket therein adapted to contact the lipof the said spinnerette, and means for coupling said end-closing memberto said elongated chamber; means including a conduit for introducing acoagulating liquid into the upper part of the said lower reservoir; andmeans including a conduit for withdrawing a coagulating liquid from thelower part of the said upper reservoir.

References Cited in the file of this patent UNITED STATES PATENTS827,434 Friedrich July 31, 1906 2,255,594 Berndt Sept. 9, 1941 2,711,559Lynch June 28, 1955 FOREIGN PATENTS 742,817 Germany May 12, 1943 333,868Switzerland Dec. 31, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION April 10, 1962 Patent No. 3,028,626

Mario Sonnino rtified that err-er appears in th tion and that the saidLetters Patent e above numbered pet- It is hereby as should reedes entrequiring correc corrected below.

Column 1 line 52, for "coagulatng' read column 3, line 53, for"connected" read conducted signed and sealed this 24th day of July 1962.

(SEAL) Attest: ERNEST w. SWIDER DAVID LADD Commissioner of PatentsAtteeting Officer

